Admitted to the Union on January 29, 1861 as the 34th state. Kansas became a territory in 1854.
- 1860—1940 federal censuses extant for all counties except for 1890.
| Allen | Anderson | Atchison | Barber |
| Barton | Bourbon | Brown | Butler |
| Chase | Chautauqua | Cherokee | Cheyenne |
| Clark | Clay | Cloud | Coffey |
| Comanche | Cowley | Crawford | Decatur |
| Dickinson | Doniphan | Douglas | Edwards |
| Elk | Ellis | Ellsworth | Finney |
| Ford | Franklin | Geary | Gove |
| Graham | Grant | Gray | Greeley |
| Greenwood | Hamilton | Harper | Harvey |
| Haskell | Hodgeman | Jackson | Jefferson |
| Jewell | Johnson | Kearny | Kingman |
| Kiowa | Labette | Lane | Leavenworth |
| Lincoln | Linn | Logan | Lyon |
| Marion | Marshall | McPherson | Meade |
| Miami | Mitchell | Montgomery | Morris |
| Morton | Nemaha | Neosho | Ness |
| Norton | Osage | Osborne | Ottawa |
| Pawnee | Phillips | Pottawatomie | Pratt |
| Rawlins | Reno | Republic | Rice |
| Riley | Rooks | Rush | Russell |
| Saline | Scott | Sedgwick | Seward |
| Shawnee | Sheridan | Sherman | Smith |
| Stafford | Stanton | Stevens | Sumner |
| Thomas | Trego | Wabaunsee | Wallace |
| Washington | Wichita | Wilson | Woodson |
| Wyandotte |